This invention relates to the production handling of pouches and, more specifically, to an improved rotary knife and transfer apparatus used in connection with a pouch form, fill, and seal machine, the knife capable of severing pouches from a pouch train and selectively discharging pouches for downstream cartoning or other packing or handling.
In typical pouch machines, a flat web of heat sealable material is continuously fed from upstream of the pouch machine and longitudinally folded upon itself by a plow or similar device. In this form, the thus-folded web is fed about a sealer which contacts the folded web along vertical heated land areas to form transverse vertical seals, and, thus, a series of open-top pouches along the web. The web of open-top pouches is passed around a filler wheel, filled with product and then sealed along the top edge of the web. The web of filled pouches then passes downstream to a motor-driven rotary knife apparatus which cuts the web along the transverse vertical seals into separate individual pouches and deposits them onto a transfer for subsequent cartoning or other secondary packaging.
In one earlier system, pouches are dropped directly from the rotary knife onto a conveyor parallel with the rotary knife axis and feeding a downstream cartoner or hand packer, for example. In another earlier system, pouches are transferred to a courier or transfer wheel which feeds a conveyor operating perpendicular to the rotary knife axis for conveying pouches to a downstream cartoner. This is frequently referred to as a xe2x80x9cdirect dropxe2x80x9d system and where the conveyor comprises buckets for receiving stacks of pouches, the conveyor as described is a direct drop bucket conveyor. It should be understood then that a direct drop conveyor could be a bucket conveyor or some other form of direct drop conveyor so long as it operates perpendicular to the rotary knife or wheel axis. In further known configuration, pouches have been dropped from both knife and transfer wheel onto two separate conveyors, parallel to the rotary knife axis, for feeding downstream cartoners wherein both conveyors operate in directions parallel to the axes of rotation of the knife and transfer wheel. These are typically not referred to as direct drop conveyors.
Prior high volume throughput packaging systems use two or more cartoners. These cartoners are typically fed by pouch systems each having a separate rotary knife for each cartoner. For example, where pouches are to be cartoned automatically, a transfer wheel is used to transfer cut pouches from a knife hub directly drop pouches in conveyor buckets feeding the cartoners. On the other hand, when pouches are shingled or to be hand-packed, they are dropped onto a shingle conveyor as noted above by the rotary knife hub itself. The limitations of these two different systems are significant.
But first, a further brief background will be helpful in appreciating the invention. It will be appreciated that past rotary knives have both major and minor knife hubs, each operating about a respective axis of rotation with each axis being parallel to the other. Examples of this configuration are disclosed in U.S. Pat. Nos. 3,597,898; 3,961,697; 4,872,382; 5,220,993; 5,222,422; and 5,575,187, each of which are herewith expressly incorporated herein by reference.
When a transfer wheel is used with such a knife, it too operates about another respective axis of rotation which is also parallel to the respective axes of rotation of the major and minor knife hubs. One prior example of such a transfer wheel apparatus is disclosed in U.S. Pat. No. 5,220,993 which is also herewith expressly incorporated herein by reference.
Pouch drop off from the major knife hub onto a conveyor operating perpendicular to the aforementioned axes of rotation is illustrated at least in U.S. Pat. Nos. 4,872,382 and 5,222,422, while pouch drop off from the major knife hub to a conveyor (other than a direct drop conveyor as defined herein) operating parallel to the respective axes of rotation is illustrated in at least U.S. Pat. No. 3,961, 697. Pouch drop off from a transfer wheel to a conveyor operating parallel to the axes of rotation is illustrated in at least U.S. Pat. No. 5,220,993.
As noted above, a further embodiment where pouches are dropped from both a major knife hub and a transfer wheel onto two separate single or multiple lane conveyors operating parallel to the aforesaid axes of rotation is also known. Where pouches are dropped from either knife hub or transfer wheel onto a conveyor parallel with their axes of rotation, the pouches are typically dropped in singled or shingled orientation for downstream hand packing or other pouch handling and orientation before packing.
Throughout this application, references are made to the direction of operation of conveyors or the direction of transport of pouches thereon. This refers to the direction of the operation of the conveyor as it receives pouches from the drop off point of a knife hub or transfer wheel, and not necessarily to any later direction of the conveyor which may be otherwise directed.
In most high speed cartoning systems, it is desirable to directly drop pouches onto a direct drop conveyor such as into a bucket of a bucket conveyor to form a select count pouch stack which is then inserted by a cartoner into a carton in a single or multiple stack format. Such a conveyor is most conveniently operated in a direction perpendicular to the axes of knife and transfer wheel orientation to facilitate dropping a select count of pouches into each bucket. Thus the duration of operative movement of such buckets is in the same direction pouches are ejected from the knife or transfer wheel. This permits pouches to be easily stacked on the conveyor and perhaps even more speed or throughput than where pouches are dropped onto a non-direct drop conveyor operating in parallel with knife or transfer wheel axis. In such a case, the direction of pouch travel is changed 90 degrees between its motion on knife hub or wheel and its conveyed motion and the duration of any target location of the conveyor under the knife or wheel in an operable or drop area is shorter than with the other conveyors operating perpendicularly to the axes of rotation. Such conveyors are thus not generally capable of producing pouches in desired stack counts and may be slower than higher conveyor speeds desired where multiple count pouch stacks are to be handled in an automated cartoner.
Of perhaps most significance, however, is the desire to use a direct drop conveyor to produce stacks of pouches and eliminate the need to have downstream transfers or other orienting devices. Where pouches are dropped onto conveyors moving in directions parallel to the knife or wheel axes of rotation, further downstream equipment is necessary to handle, combine or orient them for final packing. This requires more equipment, more complexity and more floor space, and may slow the overall throughput.
Morever, another difficulty inherent in such non-direct drop conveyors is the waste of pouches or product. When a system is stopped, or even slowed, there exists a number of pouches on the conveyor between the knife and the downstream pouch handling or cartoning apparatus. It is difficult to keep track of the number or position of these pouches, particularly when shingled, and they are frequently rejected or wasted in the subsequent start up. The waste of xe2x80x9cwork in progressxe2x80x9d, i.e. pouches, is undesirable and it is desired to be able to make any changeover or handling any system slow down or stop without wasting work in progress.
In this regard, it will be appreciated that the direct drop conveyor significantly reduces the aspect of wasted work in progress. Since the pouches are dropped directly into stacks on the direct drop conveyor, they are useful and need not be wasted; they can be packed without additional downstream transfer equipment, as contrasted to the uncertain handling of indeterminate pouches on a non-direct drop conveyor moving through downstream transfer equipment. In other words, the direct drop conveyor provides the advantage of increasing the speed of diversion of pouches between the knife and a cartoner.
It will also be appreciated that only one lane of pouches is produced onto conveyors operating perpendicular to the axes of rotation, the conveyor being in the same operational plane as the knife hub or wheel, and the single lane conveyor may not lend itself to feeding cartoners or current multiple lane equipment. Thus, direct drop conveyors are highly useful in producing stacks of pouches and without downstream transfer or additional handling equipment to place pouches into the desired stacks.
Generally cartoners of today""s design are gaining in speed, approaching, but still well under, 1000 pouches per minute. Many new pouch machines are approaching that speed, such as applicant""s own PK4000 brand pouching equipment. In considering a pouch production operation of both pouch manufacturing and pouch cartoning, it is desirable to have a throughput as fast as possible. Nevertheless, a faster pouch machine will overload a slower cartoner and thus the cartoning operation currently becomes the weak link in the system from a throughput standpoint. And in terms of cost and complexity where the knife discharges pouches onto a conveyor operating parallel to the knife axis, more downstream transfer equipment is needed.
Based on the above background, even the present rotary knife devices feeding cartoners thus appear to present an obstacle to the desired operational throughput. Even where such knives have two pouch discharge points, this only occurs onto conveyors operating in parallel with the knife or transfer wheel axes and not with direct drop conveyors conveying multiple count pouch stacks. While the volume throughput of such operations in many, if not all, cases may be insufficient to accommodate the output of the faster pouching machines even where two cartoners are fed by such knife apparatus, the use of non-direct drop conveyors requires additional transfer and pouch orienting equipment if multiple pouch packaging is desired.
In the past, it has been common practice to use a single dedicated knife apparatus feeding a single cartoner. This is particularly true when a xe2x80x9cdirect dropxe2x80x9d pouch transfer has been desired, such as by a transfer wheel depositing pouches into a bucket conveyor operating in a direction perpendicular to the transfer wheel""s axis of rotation. This has produced the best throughput operation so far without downstream transfer apparatus, but has still several operational limitations.
For example, when the pouch machine output is changed over from an automated cartoner to a shingled pouch cartoning operation, or vice-versa, the pouch web or bandoleer from the pouch machine must be redirected from one knife to another knife for the different cartoner.
This changeover process requires that the production line be temporarily shut down while the other rotary knife apparatus is threaded with the web of pouches. As can be appreciated this changeover process is costly, reduces production output, and adds to the complexity of the manufacturing process. Furthermore, an upstream festooning device is generally required to take up the slack in the pouch web which is generated when switching from one rotary knife apparatus to another if the pouch machine is not stopped. Finally, the rotary knife apparatus generally use different cutting knives depending on the type of pouch drop and conveyor system used. Consequently, the operator must keep a variety of spare parts on hand to service the different rotary knife apparatuses.
Prior attempted solutions to the knife and cartoner throughput issue have provided only partial help. For example, if the knife production of pouches onto a single conveyor is split downstream, the manufacturer may end up with two or more lanes of pouches but having been split, these are now on expanded centers or locations (i.e. conveyor load densities are split) and additional equipment is needed to recombine or reorient the pouches.
Accordingly, in handling pouches from the pouch machine to the knife and then the cartoner, it is also necessary to keep in mind the limitation of the pouch centers required by the cartoner. To be effective, the knife must produce pouches on the centers or in the densities required by the cartoners or only partial fills will result in the cartons. Thus, where any pouch discharge has been split, or provided by a conveyor orientation not up to the throughput parameters required, the entire system must be slowed and/or additional pouch handling or combining equipment must be added to the handling or packaging line.
Accordingly, a primary objective of the present invention is to provide a single rotary knife and transfer apparatus capable of selectively depositing pouches onto one or more conveyors, where at least one is a direct drop conveyor carrying the pouches to different cartoning machines.
Another object of this invention is to provide a rotary knife and transfer apparatus which provides improved operating flexibility and reduced operating costs.
Another objective of the present invention is to provide a single rotary knife and transfer apparatus capable of selectively depositing pouches onto at least one direct drop conveyor and one or more other conveyors so as to eliminate a festooning of a pouch web or bandoleer when a cartoner is stopped or taken off line.
Another objective of the invention is to provide a pouch knife and transfer having two discharges, at least one onto a direct drop conveyor and wherein waste and downstream handling or transfers are eliminated.
These and other objects of the invention are provided for by a multiple deposit pouch severing and transfer knife apparatus used in connection with a pouch form, fill, and seal machine and capable of selectively discharging pouches onto a plurality of conveyor systems for different downstream handling devices such as separate or different cartoners or packing stations and wherein at least one of the conveyor systems is a direct drop conveyor, preferably a bucket conveyor, for single or multiple pouch count stacks and operating in a direction perpendicular to the axes of rotation of rotating knife components of the knife apparatus.
In one embodiment, the pouch severing and transfer apparatus has a major rotary pouch knife hub cooperating with two transfer wheels. The rotary pouch knife defines two release stations where pouches are released from the hub onto the respective transfer wheels which have peripheral suction cups operably positioned proximate the periphery of the major knife hub at the respective release stations. Axes of the major knife hub and the wheels are all parallel. The first wheel is disposed at the first release station and the second transfer wheel is operably disposed adjacent to the rotary pouch knife at the second release station. The first wheel transfers pouches to one drop off area over a direct drop bucket conveyor. The second transfer wheel receives pouches at the second release station for transfer to another drop off position feeding a second downstream handling device, preferably another direct drop conveyor, such as a bucket conveyor. Advantageously, the two conveyors are each operably disposed respectively between the rotary pouch knife and the downstream handling devices, each receiving pouches from one of the two transfer wheels and transferring pouches to respective downstream handling devices, and at least one of the conveyors and, in this case, both conveyors, being direct drop conveyors, preferably bucket conveyors. As used in this description, a downstream handling device may be a pouch recombining device, a pouch orientation device, a pouch packing or pouch cartoner or the like.
In another embodiment, the pouch severing and transfer apparatus has a major rotary knife hub cooperating with only one transfer wheel. In this embodiment, the rotary pouch knife is adapted to sever pouches from a pouch train and to carry separated pouches to at least one of at least two release stations located about the major rotary pouch knife hub. At least one transfer wheel is operably disposed adjacent to the rotary pouch knife hub at one of the release stations for receiving pouches at the one release station from the rotary pouch knife and transferring such received pouches to a drop off position from where it is conveyed to one downstream handling device. A second one of the release stations, which is spaced from the first release station, also comprises a drop off point and can release pouches directly from the rotary pouch knife onto a shingled or multiple lane conveyor operating in a direction in parallel to the rotational axes of the knife for transfer to a second one of the downstream handling devices. Advantageously, the pouch severing and transfer apparatus includes two conveyors, one conveyor being a direct drop conveyor, preferably a bucket conveyor, receiving pouches from the transfer wheel and for transferring those pouches to one downstream handling device, and the other conveyor for receiving pouches directly from the rotary pouch knife (not from the transfer wheel) and transferring them downstream in another direction.
Accordingly, in each of these embodiments, the apparatus includes at least one transfer wheel and at least two pouch drop off points or areas disposed operably over at least two take away conveyors, one being a direct drop conveyor operating in a direction perpendicular to the axes of rotation of the knife or transfer wheel feeding the conveyor.
In this way, the knife apparatus has the advantage of at least one direct drop conveyor for efficiently feeding at least one cartoner and a secondary discharge of either another direct drop conveyor, operating in a direction perpendicular to the rotational axes, or a conveyor operating in a parallel direction with respect to the rotational axes and at least carrying other pouches. Thus, the knife is capable of handling the full throughput of the pouching machine by having the capacity to effectively feed that full output through separate discharges to two, or even more, cartoners.
It will be appreciated that the invention contemplates many variations of the basic concept which is a rotary knife apparatus having at least two pouch discharges, at least one of which feeds a direct drop conveyor and the other of which is a second conveyor operating in a parallel direction with the direct drop conveyor or in a direction perpendicular to it. And the knife apparatus itself may preferably comprise a major rotary knife hub, a minor knife hub, at least one transfer wheel and, optionally, two. The direct drop conveyor is preferably a bucket conveyor but may be any other form of direct drop conveyor operating perpendicularly to the axis of the knife or wheel feeding it.
Other embodiments are set forth in the following written description.
Accordingly, the improved knife apparatus according to the invention provides a single knife apparatus where only one pouch train is severed and the pouches can be delivered to at least one or two drop offs for conveyance to at least two cartoners or packing stations or downstream handling devices. It is no longer necessary to provide a single dedicated knife for each cartoner packaging line. Overall throughput is increased, the knife output can be directed more readily to one or both of two cartoners and a manufacturer no longer must spend money on a separate knife for each cartoner line. Pouch train accumulation or festooning due to downstream shut downs or delays is minimized or avoided, as is the need for downstream transfer or handling equipment.
These and other advantages will become readily apparent from the detailed description of preferred and other embodiments of the invention, and from the drawings in which: